Add a note on how to contribute

also testing gitlab mirroring MRs with this commit

README.rst

@@ -9,5 +9,15 @@ Documentation
 
 maintained at https://boxmodeling.meteo.physik.uni-muenchen.de/documentation
 
+Contributing
+============
+
+We are happy to receive your [new issue report](https://mbees.med.uni-augsburg.de/gitlab/mbees/icartt_pypackage/-/issues/new).
+
+If you'd like to contribute source code directly, please [create a fork](https://mbees.med.uni-augsburg.de/gitlab/totallylegit/icartt_pypackage),
+make your changes and then [submit a merge request](https://mbees.med.uni-augsburg.de/gitlab/totallylegit/icartt_pypackage/-/merge_requests/new) to the original project.
+
+
 Installation
-============
\ No newline at end of file
+============
+